Chemistry Quantum Mechanic P1

Question 1

Electromagnetic Radiation

Answer 1

A type of energy that travels through space at a constant speed of 3.00 x
108 m/s

Question 2

Photon

Answer 2

A photon is a single “packet” of electromagnetic radiation. Photons can be considered
particles, but they have no mass

Question 3

Amplitude

Answer 3

The height of a wave crest.

Question 4

Wavelength

Answer 4

The distance between adjacent crests in a wave

Question 5

Frequency

Answer 5

The number of cycles to pass through a stationary point in a given time. Usually measured
in Hertz (Hz) or cycles per second (s-1)

Question 6

Planck’s Constant

Answer 6

6.626 x 10-34 J * s

Question 7

Emission Spectrum

Answer 7

Wavelengths of light emitted by a particular element. The emission spectrum of
each element is unique and can be used to identify the element

Question 8

Nuclear Model of the Atom

Answer 8

Model of the atom in which most of the atom’s mass, and all of its
positive charge, is concentrated in a small area called the nucleus. The nucleus us surrounded by a
negatively-charged electron cloud

Question 9

Bohr Model of the Atom

Answer 9

A model of the atom in which electrons can only orbit the nucleus at specific
fixed “distances

Question 10

Quantum Mechanical Model of the Atom

Answer 10

A model of the atom in which electrons occupy orbitals –
regions of space where an electron is likely to be found

Question 11

Diffraction

Answer 11

When a wave passes through a small opening, it spreads out. Each opening acts as a new
wave source

Question 12

Constructive Interference

Answer 12

When two waves with overlapping crests interact, the result is a wave with
twice the amplitude

Question 13

Destructive Interference

Answer 13

When the crest of one wave overlaps with the trough of a different wave,
they cancel each other out

Question 14

Two-Slit Experiment

Answer 14

An experiment that was used to demonstrate the wave-like nature of light and
electrons. When a beam of light, or electrons, passes through two slits, the resulting waves interfere

Question 15

The de Broglie Wavelength

Answer 15

Quantifies the wave-like nature of matter

Question 16

Complementary Properties

Answer 16

Properties that cannot be observed simultaneously. The more that is
known about one property, the less is known about the other

Question 17

Heisenberg’s Uncertainty Principle

Answer 17

The principle stating that due to the wave-particle duality, it is
impossible to precisely determine both the position and velocity of a particle at the same time.

Question 18

Orbitals

Answer 18

Regions of space where an electron is likely to be found.

Question 19

Shell

Answer 19

Shells are regions of space around an atom that can hold many orbitals. Each row of the periodic
table corresponds to a shell

Question 20

Orbital Types

Answer 20

There are four types of orbitals: s, p, d, and f. Each type has a different shape

Question 21

Degenerate Orbitals

Answer 21

Orbitals that have the same energy

Question 22

List 3 different types of electromagnetic radiation

Answer 22

Radiowaves, microwaves, gamma rays, x rays, visible light, uv light

Question 23

T/F Electromagnetic radiation has particle-like properties and wave-like properties.

Answer 23

True

Question 24

How do atoms emit light

Answer 24

When electrons fall from high to low energy state

Question 25

What devices can be used to separate light into constituent colors, each with different energy?

Answer 25

Prism

Question 26

Why did the discovery of the emission spectrum suggest the nuclear model revision

Answer 26

Nuclear model could not explain individual lines in emission spectrum

Question 27

Why is the quantum mechanical model necessary? What flaws are in the Bohr model?

Answer 27

Bohr model only addresses hydrogen, We need it for other elements as well.

Question 28

Since de Broglie wavelength applies to all objects regardless of size. Why cant we observe wave-like properties of macroscopic items like baseballs?

Answer 28

1. mass is too large compared to electron; causes the wavelength to decrease
2. wavelength goes unnoticed due to size difference

Question 29

T/F In quantum mechanics, the observation of an event affects its outcome.

Answer 29

True

Question 30

Why does Heisenberg’s uncertainty principle cause orbitals to be considered regions of 3-d space where electrons are likely to be found rather than the path electrons travels?

Answer 30

The principle tells us that we cant know both velocity and position at the same time. Therefore we cant find its path traveled.

Question 31

T/F orbitals represent the path traveled by an electron

Answer 31

False